Antiepileptic drugs and lipid-lowering agents in surface water in Colombia: occurrence, ecological threat, and removal strategies

The presence of pharmaceuticals in water poses emerging environmental risks to aquatic ecosystems and potentially human health. This study investigates the occurrence and ecological threat of antiepileptic drugs and lipid-lowering agents in surface water, specifically in the Cauca River, one of the most important rivers in Colombia. Quantification was conducted using liquid chromatography coupled with mass spectrometry. Additionally, conventional physicochemical parameters were evaluated. The hazard associated with the compounds was assessed using the persistence, bioaccumulation, and toxicity (PBT) index. The ecological threat was determined via the Hazard Quotient (HQ) and Toxic Units (TU). A literature review was also performed to evaluate existing treatment systems for their removal. Among a total of 11 pharmaceutical compounds analyzed, 5 were detected. The findings revealed the presence of antiepileptic drugs such as carbamazepine (CBZ), 10,11-dihydro-10,11-dihydroxycarbamazepine (CBZ-Diol), and gabapentin (GBP). Detected lipid-lowering agents included fenofibric acid (FFA) and gemfibrozil (GFZ). Concentrations of up to 92 ng.L⁻¹ were found for GFZ and CBZ-Diol. Physicochemical alterations were observed near wastewater discharge points. The PBT index indicated medium hazard for CBZ, CBZ-Diol, FFA, and GFZ, whereas the HQ revealed medium ecological risk for CBZ, with TUs corroborating these findings. Findings underscore the need for pharmaceutical monitoring and management in water sources. Removing these compounds remains challenging due to their variable removal patterns, necessitating the development of effective mitigation strategies.

Graphical Abstract